Project description:Prognosis of glioblastoma remains poor despite a great deal of research. In glioblastoma, the existence of glioblastoma stem cells (GSCs) has been shown, which are responsible for tumorigenesis, invasive capacity, and therapy resistance. One of cancer stem cell markers, Leucine-rich repeat-containing G-protein coupled receptor (Lgr5) plays a role in maintenance of GSCs, however, properties of the Lgr5 positive GSCs have not been fully understood. We applied the Sleeping-Beauty transposon-induced glioblastoma model to the Lgr5-GFP transgenic mice and sorted the GFP-positive cells from the neurosphere cultures derived from the mouse glioblastoma tissues. We found that the GFP-positive GSCs exhibited higher expression of Gli2 using a global gene expression analysis.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Glioblastoma multiforme (GBM) is a lethal malignancy whose clinical intransigence has been linked to extensive intra-clonal genetic and phenotypic diversity and therapeutic resistance of cancer stem cells (CSCs). This interpretation embodies an implicit assumption that CSCs are themselves genetically diverse. To test this, we screened neurosphere cultures by SNP arrays to identify copy number alterations (CNA) (minimum of three) that could be visualised in single cells by multi-colour FISH. Interrogation of neurosphere-derived cells (from four patients) and cells derived from secondary transplants of these same cells in Nod/Scid mice allowed us to infer clonal phylogenic architecture and the likely derivation of functional CSCs. This proof-of-principle experiment revealed that more than one sub-clone (but not all) in each GBM had functionally defined, genetically distinct stem cells.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:RNA-sequencing (RNA-Seq) protocols and bioinformatic pipelines are designed to streamline downstream analyses on sequences believed to be the most important. Here, we have challenged this dogma by preserving ribosomal RNA (rRNA) in our samples and by lowering the minimal RNA size window of our small RNA-Seq analyses to 8 nt